This invention relates to a device which facilitates the replacement of the upper rear oil seal in an internal combustion engine.
As is well known, an engine has a lower seal and a matching upper seal which extend around the crankshaft to prevent the leakage of oil. The seals are strips of jute type material having a tar base and the lower seal is mounted in a semicircular lower seal retainer which is bolted to the engine block. The upper seal is similarly securely mounted in a curved inner groove in a semicircular metal upper seal retainer. The upper seal retainer has an outer flange which is received in a groove in the engine block to frictionally secure the seal and retainer unit in a tight sealing position between the block and the crankshaft.
When the seals wear and start to leak, they must be replaced. This is done by removing the seal and seal retainer, replacing the worn seal by a new seal, and reinstalling the seal and retainer unit. This is a relatively simple procedure for the lower seal, as the lower seal retainer can be removed by simply unbolting it from the engine block. However, the normal procedure for replacing the upper seal is much more difficult and very time consuming. While the seal and seal retainer can usually be slid lengthwise out of the curved groove in the block by tapping on one end with a hammer and punch, the problem arises in trying to reverse the procedure after the new seal has been installed. While one end of the seal retainer can be started in the groove, it has been found that tapping on the other end of the seal retainer merely jams it due to its semicircular shape and the frictional forces against the block and crankshaft. Thus, the standard procedure for replacing upper rear seals of this type is to remove the crankshaft, remove the seal retainer and replace the seal, and then reinstall the crankshaft. As will be appreciated, this is a time consuming and expensive procedure to simply replace a leaking seal.
Earlier attempts to simplify the procedure for replacing real seals are shown in U.S. Pat. Nos. 2,621,398 to Simmons which issued Dec. 16, 1952 and 3,084,423 to Fullerton which issued Apr. 9, 1963. Both of these prior patents relate to the concept of gradually "funneling" the seal as it is drawn into a groove in the engine block. However, this does not relate to the present case where the seal is mounted on a rigid seal retainer which is then driven into the groove in the block.